for any organization there is the
potential for disaster to occur so our
planning process needs to take into
account a number of strategies that can
help us if we ever need to perform a
disaster recovery of course you should
always have a backup but there are many
different kinds of backups that you can
create for example you may want to
create an image level backup this is a
backup that incorporates everything
that's in a particular server or device
and creates a single image from all of
that data this is sometimes referred to
as a bare metal backup because if you
wanted to restore from this backup you
could take a separate server with no
operating system that's referred to as
the bare metal and apply this image
applying that image would restore every
file on that device giving you a fully
functional service many operating
systems have a volume snapshot function
built into the OS and if you're running
this as a virtual machine you can easily
create an image for that entire VM this
not only allows you to recover the
entire system with this single image but
you could take that image to another
computer to create an exact duplicate of
this server another type of backup
strategy is the file level backup where
you're simply copying the important
files that are stored on that device you
may not be copying the entire operating
system but you'll have all of the files
necessary to get your applications
running this means if you need to
recover this particular application
you'll need to find a device that at
least has an operating system running
and from there you can restore your
applications and files on that existing
OS restoring an application may be
relatively simple or it may involve
multiple devices and have a level of
complexity associated with it some
applications will distribute the
software across multiple servers and all
of those servers have to work together
for that application to operate properly
not only is the application important
but the data that is used for the
application is just as important
sometimes this is stored in a separate
database so you would need a database
server with all of that data loaded or
sometimes the data is stored in
different places on the application
servers sometimes this information is
not on your local servers but it's
instead stored on a cloud service
perhaps provided by the application
developer you might have a combination
of data stored locally and data stored
in the cloud so it's important to know
where this data is before you begin the
backup and recovery process for complex
applications it's useful to document
this process prior to having a problem
that way you know exactly what needs to
be recovered during the disaster
recovery process often mentioned in my
videos that you must have a backup of
your data but having the backup is only
part of the equation you have to be able
to restore the backup and if you're
trying to recover from a disaster you
don't want that to be the first time
that you've ever tried to restore this
data many organizations will perform
some type of disaster recovery testing
during the year this gives you a chance
to take the data that you've backed up
perform a restoration and see if
everything works as expected
once the restoration is complete you can
use the application make sure the data
is working properly and have the end
users confirm that everything is working
as expected during the year when you're
not performing these tests you may want
to perform occasional audits to make
sure that the backups are working
properly and the data is stored as
expected when a disaster occurs you may
have an intermittent power loss to be
able to mitigate this power loss you may
want to have a UPS which is an
uninterruptible power supply this will
give you short-term powers that you're
able to keep everything running even
though there's no main power source
available a UPS will protect you when
you lose all power such as a blackout
when there's a drop in voltage which is
a brownout or when there is a spike of
voltage which would be a power surge
there's generally three categories of
UPS that you could choose from an
offline or standby UPS is constantly
watching the voltage from the main power
if that main voltage disappears it goes
from offline in standby mode into an
online mode and switches all of the
power to come from the batteries that
are in the UPS when the main voltage
comes back it switches back to the main
voltage line a line interactive UPS can
slowly ramp up how much power it's
providing so if you have a brownout
or a little bit of voltage is lost on
the line the UPS can provide additional
voltage from the bad
and in many data centers you run an
online or double conversion ups where
you are always running from a battery
configuration and there is no switching
over if you lose the mainline
configuration the main line is
constantly refreshing the batteries and
the batteries running in the system are
providing the main voltage if you ever
do lose the main voltage there is no
switching over or delay while you're
waiting for the UPS to kick in from an
offline mode there are also different
features available on different UPS
models some have an auto shutdown
feature which will tell the computer
it's connected to to begin the shutdown
process because the main power is failed
there's also differences in the amount
of battery capacity and outlets and some
ups also have interfaces for phone lines
or other network connections another
type of power protection is a surge
suppressor the power that's coming in
from your main voltage line may have
spikes and noise that are created by
changes in the electrical system or by
storms that may be coming through the
search suppressor will notice when these
spikes occur and will take that
additional voltage and send it to the
electrical ground some surge suppressors
have filters that can remove some of the
noise that would appear on an electrical
line if you look at the specifications
for a surge suppressor you'll notice
this filter is listed as a number of
decibel levels and the higher DB means
that you have a better filter in that
surge suppressor many people will store
their backups and other important data
in a cloud-based storage solution this
may be the cloud solutions from Amazon
Microsoft and many others these cloud
solutions allow you to keep all of this
data off-site on these third-party cloud
servers without having to deal with any
local backups or data inside of your
building this means that you don't have
to have any local backup servers or tape
drives and you don't have to worry about
taking the data off-site since the data
has already been backed up to the cloud
which exists on servers that are already
off-site when you're storing your data
on a third party server though you're
losing a bit of control over the access
to that information so you want to be
sure that you're able to put in the
proper security measures
that nobody else can see that
information it's a good idea to encrypt
your data before storing it in the cloud
so that nobody can access that
information if they happen to gain
access to your cloud credentials once
you bring up all of these systems in
your disaster recovery process there
still needs to be some way for people to
log in so you have to make sure that
your centralized authentication
functions are still in place for Windows
domain you will have a backup that has
all of your usernames passwords and
everything else associated with your
users credentials for disaster recovery
you also have to consider if you're
using the type of multi-factor
authentication and either enable or
disable those features as well there
might also be additional authentication
databases that you're using for instance
people who are logging into a switch or
a router may be connecting to a third
party database using tack ax or radius
if you're backing up your centralized
authentication method then you know that
you're able to restore those
authentication methods if you run into a
problem this is another good reason to
avoid having local accounts on these
devices so that you're able to manage
all of your credentials centrally and be
able to backup and restore them if
there's a problem
you